Java之二元运算

二元运算+ - * / %

public class Demo4{    public static void main(String[] args){        //加法运算        System.out.println(10 + 20); //30        //字符串拼接        System.out.println("10"+"20"); //1020        int i1 = 100;        int i2 = 200;        int i3 = i1 + i2;        System.out.println("i3=" + i3);//300int num1 = 9;        int num2 = 2;        //在除法运算过程中，如果运算符两侧的类型都为int，那么它们最终做的是取整操作，不是四舍五入        int num3 = num1 / num2;        double num4 = num1 / num2;        System.out.println("num3=" + num3); //4        System.out.println("num4=" + num4); //4.0double num5 = num1 / (2 * 1.0);        System.out.println("num5=" + num5); //4.5        //计算一下：35占87的百分之多少        System.out.println(35 / 87.0 * 100 + "%"); //40.229885057471265%        //做取模运算，最终的正负号和被模数的正负一致        System.out.println(5 % 2);      //1        System.out.println(5 % -2);     //1        System.out.println(-5 % 2);     //-1        System.out.println(-5 % -2);    //-1    }}